When Exelon Generation shut down Three Mile Island Unit 1 in September 2019, managers were so certain that the reactor would never run again that as soon as they could, they had workers drain the oil out of both the main transformer and a spare to eliminate the chance of leaks. The company was unable to find a buyer because of the transformers’ unusual design. “We couldn’t give them away,” said Trevor Orth, the plant manager. So they scrapped them.

Now they will pay $100 million for a replacement.

The turnaround at the reactor—now called the Crane Clean Energy Center—highlights two points: how smart Congress was to step in with help to prevent premature closures with the zero-emission nuclear power production credit of 0.3 cents per kilowatt-hour (only two years too late), and how expensive it is turning out to be to change course.